MXPA05001522A

MXPA05001522A - Systems and methods for the high temperature application of pumpable fibrous refractory material.

Info

Publication number: MXPA05001522A
Application number: MXPA05001522A
Authority: MX
Inventors: Kevin D Pendleton
Original assignee: Fosbel Intellectual Ag
Priority date: 2002-08-07
Filing date: 2003-07-30
Publication date: 2005-08-19
Also published as: US20040250761A1; ZA200501473B; AU2003263396B2; US7169439B2; NO20051200L; US7114663B2; CA2494958A1; EP1527307A2; WO2004014565A3; WO2004014565A2; US20040037955A1; AU2003263396A1

Abstract

Systems (10) and methods are provided whereby pumpable viscous fibrous material may be applied onto surfaces of high temperature process vessels (12) while hot (i.e., while at or near such vessels' high operational temperatures of several hundreds up to several thousands of degrees Fahrenheit). More specifically, there are preferably provided a lance (14,30) having a nozzle structure (14-5) at a distal end thereof, and a pump system (18) for pumping a pumpable fibrous refractory material to the nozzle (14-5). The lance (14) has a length sufficient to allow it to be inserted into the high temperature process vessel (12) so that the nozzle structure (14-5) is adjacent an area in need of repair while an operator holds a proximal end thereof outside the vessel (12). In use, the lance (14,30) is inserted into the process vessel (12) while the process vessel (12) is at or near its high operational temperature so that the nozzle structure (14-5) is positioned adjacent to an area of the process vessel wall in need of repair, and so that the lance (14,30) may be manipulated from outside the process vessel (12) during repair of the wall thereof. Manipulating the lance (14,30) from outside the process vessel will thereby cause the atomized spray of the fibrous material to contact the wall of the process vessel (12) thereby repairing the same.

Description

SYSTEMS AND METHODS FOR THE APPLICATION TO ELEVATED TEMPERATURE OF REFRACTORY MATERIAL, FIBROUS, THAT CAN BE PUMPED FIELD OF THE INVENTION The present invention relates, in general, to the systems and methods by which fibrous refractory material can be applied on surfaces of process vessels at elevated temperatures when they are at elevated temperatures or near their elevated operating temperatures.

BACKGROUND AND COMPENDIUM OF THE INVENTION High temperature process vessels (e.g. ovens, drying ovens, melting furnaces, and the like) are used in various industries. Typically, the surfaces of the walls of these high temperature process vessels have an internal coating or coating formed of a high temperature refractory material. These internal refractory coatings or coatings sometimes need to be repaired, especially during the latter part of their operating cycles.

A well-known technique for repairing refractory wall surfaces of process vessels at elevated temperature while at or near high operating temperatures is commonly referred to as "ceramic welding". More specifically, the techniques of ceramic welding are carried out while the refractory lining is still hot to minimize the unproductive time of the process vessel and to prevent cracking of the lining that could occur with cooling due to or its operating temperatures. . During the ceramic welding, a stream of solder particles (usually a particulate mixture of metals and metal oxides) is driven in a stream of a gaseous fluid, preferably air, through an elongated lance cooled with fluid (so regulate water). The impact of particles on the refractory lining area to be welded and, due to the high temperature of this lining, the particles melt to form a ceramic solder thereon. During use, the lance is inserted into the process vessel when it is at or near its high operating temperatures, for example, at or near several hundred degrees Fahrenheit (eg, approximately 500 ° F) up to several thousand degrees Fahrenheit (for example from 1000 to approximately 3000 ° F). The operator physically holds the proximal end of the spear out of the process vessel, and handles the spear to place the far end next to the area that needs to be welded. The operator is therefore protected from the extreme high temperatures that exist within the process vessel, but can nonetheless direct the stream of particulates towards the refractory lining inside the vessel by virtue of the liquid-cooled lance. (See, in general, US Patent No. 3,684,560, the total content of which is expressly incorporated herein by reference.) Some refractory coatings are fibrous structures which, prior to the present invention, have not been repaired using ceramic welding or other hot repair techniques. In this regard, unlike the particulate materials that can be entrained in pressurized gas and driven through the heat-protected lance, the precursor fibrous refractory materials are usually in the form of a relatively viscous paste material that can be pumped. As such, the material can only be atomized just before being applied on a surface. For this reason, fibrous refractory materials have previously been applied to the surfaces of process vessels when they are cold.

Therefore, it would be highly desirable if the refractory, fibrous, viscous (paste-like) materials that can be pumped, could be applied to the internal surfaces when they are hot (i.e., while the process vessel is at or near its operating temperatures). high). It is towards the arrangement of these techniques and systems that the present invention is directed.

In a broad sense, the present invention is incorporated into the systems and methods by which fibrous, viscous, pumpable material can be applied on surfaces of process vessels at high temperature when hot (i.e. found at or near the elevated operating temperatures of vessels of several hundred to several thousand degrees Fahrenheit).

More specifically, in accordance with a preferred system for repairing fibrous refractories on walls of a high temperature process vessel according to the present invention, there is provided a lance having a nozzle structure at a distal end thereof, and a system For pumping a refractory, fibrous material, which can be pumped, to the nozzle, the lance is of sufficient length to allow the lance to be inserted into the process vessel at a high temperature so that the structure of the nozzle is adjacent to the nozzle. an area in need of repair while an operator holds a proximal end of it out of the container.

More preferably, the lance of the present invention will include a material supply tube in communication with the structure of the nozzle to direct the fibrous material that can be pumped from the pumping system to the structure of the nozzle. In the lance, cooling liquid inlet and discharge ducts are arranged to allow the circulation of a refrigerant (eg water) through the lance to protect the lance from the elevated temperatures inside the process vessel. It is important to note that a atomizer tube as a component part of the lance to be in thermal communication with it. The atomizing tube has an inlet at the proximal end of the lance to be placed outside the process vessel, and a discharge end in which the fluid communicates with the material supply tube next to the structure of the nozzle. The introduction of an atomizing gas through the tube will therefore atomize the fibrous material that can be pumped upon discharge through the structure of the nozzle.

During use, according to the method for repairing a fibrous refractory wall of a high temperature process vessel, according to the present invention, a lance cooled by a protective liquid having an atomizing tube in thermal communication with it is inserted in the process vessel while the process vessel is at or near its elevated operating temperature so that a nozzle structure of the lance at a distal end thereof is placed adjacent to an area of the process vessel wall that needs be repaired, and so that the lance can be handled from outside the process vessel during the repair of the wall of this. A fibrous, viscous refractory material can then be pumped from a source thereof from the proximal end of the lance to the structure of the nozzle at the distal end of the lance, while an atomizing gas is directed through the atomizing tube. In this form, the atomizing gas causes the fluid fibrous refractory material to be discharged from the nozzle structure of the lance in the form of an atomized spray. The handling of the lance from the outside of the process vessel will thereby cause the atomized spray of the fluid fibrous material to come into contact with the wall of the process vessel thereby repairing it.

These, and other, aspects and advantages of the present invention will become more apparent from the following detailed description of the preferred exemplary embodiments thereof.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Hereinafter reference will be made to the accompanying drawings, in which like reference numbers along the different figures indicate similar structural elements, and where: Figure 1 is a schematic representation of a representative embodiment of a system in accordance with the present invention during use for repairing the fibrous refractory lining of a high temperature process vessel; Figure 2 is a cross-sectional view of an embodiment of a liquid-cooled lance according to the present invention; Figure 3 is a cross-sectional view of the lance shown in Figure 2 taken along line 3-3 thereof; Figure 4 is a cross-sectional view of another embodiment of a liquid-cooled lance in accordance with the present invention; Y Figure 5 is a cross-sectional view of the lance shown in Figure 4 taken along line 5-5 therein.

DETAILED DESCRIPTION OF THE INVENTION An exemplary system 10 for applying a viscous, fiber-containing refractory material that can be pumped onto the interior wall surfaces of a high temperature process vessel 12 when it is "hot" (i.e. while the container 12 is at or near its elevated operating temperatures) is shown in accompanying Figure 1. System 10 typically includes a fluid-cooled lance 14, a source 16 of fibrous, viscous, pumpable refractory material, and a pump 18 for transferring material from source 16 thereof to a material inlet tube. 14-1 at the near end of the lance 14.

Almost any gas or coolant can be used to protect the lance 14 from heat. Preferably, the coolant is water, but any other gas or coolant can be used as desired for the specific repair operation. For convenience, the water in the future will be referred to as the refrigerant and thus the spear 14 onwards will sometimes be referred to as "water cooled" in view of the fact that the use of water as a refrigerant is usually preferred.

At its proximal end, the lance 14 also includes an inlet conduit arm 14-2 for introducing cooling water into the lance 14, and a discharge conduit arm 14-3 to allow the cooling water to be discharged therefrom. A spray line 14-4 follows the lance 14 along its length to allow the pressurized air to be directed to a remote atomizing nozzle structure 14-5. As will be described in more detail below, the distal nozzle 14-5 of the lance 14 allows the atomized fibrous material to be sprayed onto the surfaces of the inner wall of the process vessel 12.

The lance 14 shown in Figure 1 is shown in more detail in accompanying Figures 2 and 3. In this sense, the lance 14 is formed in general of concentrically arranged internal and external cooling tubes 20, 22 which collectively and concentrically surround the material supply tube 24. The internal and external cooling tubes 20, 22 are connected in hydraulic form respectively to the arms of the inlet and outlet ducts 14-2 and 14-3, while the material supply tube 24 is connected hydraulically to the inlet of material 14-1. As briefly stated in the foregoing, the lance 14 is of sufficient length to allow the operator to physically remain outside the process container 12 during operation, and at the same time allow the atomized material that can be pumped to be applied in the locations desired on the surfaces of the interior walls of the container.

The cooling tubes 20, 22 and the material supply tube 24 are blocked at their most distant ends by means of the stopper element 25. The cooling water flows in the tubes 20, 22 thus communicating respectively with the internal and external short tubes 20- 1, 22-1, while the material flow in the supply tube 24 communicates with the short tube of material 24-1 which is connected to the nozzle plug 26 so that the material can be ejected through the orifice of the nozzle 26-1. The inner short cooling tube 20-1 ends close to the nozzle plug 26. As such, the cooling water introduced into the lance through the conduit arm 14-2 flows into the annular space between the inner tube 20 and the material supplying tube 24, and is redirected towards the inner short tube 20-1. The cooling water then flows into the annular space defined between the inner and outer short tubes 20-1, 20-2 by virtue of which the first ends before the nozzle plug 26. As such, the cooling water is returned to the arm. of the discharge conduit 14-3 within the annular space defined between the internal and external refrigerant tubes 20, 22.

Important for the present invention is the presence of the rigid atomizing pipe 14-4 which is physically fixed to, and therefore is in thermal communication with, the external cooling pipe 22. Thus, the atomizing air within the pipe 14-4 it is cooled to the full length by virtue of the cooling water circulating within the annular space between the internal and external cooling tubes 20, 22, respectively (ie, since the tube 14-4 is in thermal communication with the outer tube 22 ). The terminal end 14-4a of the tube 14-4 is redirected through the plug 25 to be placed concentrically within the short supply tube 24-1 material. As such, the pumpable fibrous material that is supplied to the short tube 24-1 through the inlet tube 24 is atomized by the pressurized air which is discharged from the terminal end 14-4a of the tube 14-4 and thereby it is sprayed from the nozzle orifice 26-1 of the nozzle plug 26 onto the wall of the container 12. Preferably a valve 1 -4b is provided in the proximal portion of the lance 14 to allow the operator to control the atomization of the material fibrous.

An alternative embodiment of a lance 30 in accordance with the present invention is shown in accompanying Figures 4 and 5. In this regard we will note that the lance 14 shown in Figures 2 and 3 is especially useful for directing an atomized spray of the fibrous material that it can be pumped in the lateral direction (for example at a right angle) in relation to the elongated axis of the lance, while the lance 30 allows the fibrous material that can be pumped, atomized, to be sprayed, in general, in the same direction as the elongated shaft of the lance. As such, the lances 14, 30 can be used as necessary to apply the fibrous material that can be pumped onto small portions of the inner walls of the process container 12.

In the same way as the lance 14 described above, the lance 30 shown in FIGS. 4 and 5 has a material inlet tube 30-1 (similar to tube 14-1) and cooling water inlet and outlet pipes 30-2. and 30-3 (similar to conduits 14-2, 14-3, respectively). The material inlet tube 30-1 is in hydraulic connection with a material supply tube 32 which is concentrically surrounded by a cooling water outlet pipe 34 in hydraulic connection with the water inlet conduit 30-2. Multiple pipes providing cooling water 36a, 36b and 36c are physically located within the annular space defined between the material supply tube 32 and the cooling water outlet tube 34 (see Figure 5).

The cooling water supplied to the inlet conduit 30-2 in this way enters the proximal end of the pipes 36a-36c. (It will be appreciated in this regard that, because of the cross section of the lance 30 in Figure 4, only the tubes 36a and 36b are visible therein) Since the terminal ends of the tubes 36a-36c end near the stopper the nozzle 38 at the most distant end of the lance 30, the cooling water will then flow into the annular space defined between the material supply tube 32 and the cooling water outlet pipe 34, and then towards the cooling water discharge conduit 30-3.

The atomizing pipe 40 is, like the pipes 36a-36c, physically placed in the annular space defined between the material supply pipe 32 and the cooling water discharge pipe 34. Thus, the atomizing pipe 40 is in direct thermal communication with the cooling water which flows into the annular space thereby protecting it from the environment at elevated temperatures within the process vessel 12. The distal end 40-1 of the atomizing pipe 40 projects towards the supply tube 32 proximal upstream of the nozzle plug 38. More preferably, the distal end 40-1 of the atomizing pipe 40 is aligned coaxially with the nozzle orifice 38-1 and the elongated shaft of the lance 30. Preferably, the a valve 42 in the atomizing tube 40 in the proximal portion of the lance 30 to allow the operator to control the atomization of the fibrous material.

The fibrous material that can be pumped, specific, that can be handled by the systems and techniques of the present invention is not crucial. A variety of refractory fibrous materials that can be pumped are known in the art and are commercially available from numerous sources. For example, fibrous materials that can be pumped to the commercial disposal of Unifrax Corporation of Niagara Falls, New York can be employed with very good results. In general, these fibrous materials that can be pumped have a putty-like consistency (for example a viscosity of about cP or greater) with a wet density of between about 65 to about 90 lb / ft3 (usually between about 70 to about 85 lb / ft3) containing between about 20 to about 60% solids ( fibers).

Although the invention has been described in relation to what is currently considered the most practical and preferred embodiment, it should be understood that the invention is not limited to the described modality, but on the contrary, it is intended to cover the different modifications and equivalent arrangements included within. of the spirit and scope of the appended claims.

Claims

1. A system for repairing with fibrous refractory material the walls of a high temperature process vessel, consisting of: a lance having a nozzle structure at a distal end thereof, and a pumping system for pumping a fibrous refractory material, that can be pumped, to the nozzle, where the lance is of sufficient length to allow the lance to be inserted into the process vessel at a high temperature so that the structure of the nozzle is adjacent to an area that needs repair while a operator holds a proximal end thereof outside the container, and wherein the lance includes: (i) a material supply tube in communication with the structure of the nozzle to direct the fibrous material, which can be pumped, from the pumping system to the structure of the nozzle, (ii) inlet and discharge conduits for allowing the circulation of a refrigerant through the lance to protect the lance from the elevated temperatures within the process vessel, and (iii) an atomizing tube having an inlet at the proximal end of the vessel. the lance to be placed outside the process vessel, and a discharge end in hydraulic communication with the material supply tube next to the structure of the nozzle to atomize the fibrous material that can be pumped after unloading through the structure of the nozzle.

2. The system of claim 1, characterized in that the atomizing tube is fixed to a surface of the inlet or discharge ducts so that it is in thermal communication with it.

3. The system of claim 1 or claim 2, characterized in that the material supply tube is positioned concentrically within the inlet duct to define an annular space therebetween, and wherein the atomizing tube is placed within the annular space.

4. The system of any of the preceding claims, characterized in that the structure of the nozzle is positioned to direct a current of the refractory material, fibrous, which can be pumped, atomized, in the lateral direction in relation to the lance.

5. The system of any of the preceding claims, characterized in that the structure of the nozzle is positioned to direct a current of the refractory material, fibrous, which can be pumped, atomized, in the longitudinal direction in relation to the lance.

6. A heat-protected lance for repairing with fibrous refractory material the walls of a high temperature process vessel, consisting of: a tubular lance structure of sufficient length between the proximal and distant ends thereof to allow the insertion of the structure of the tubular lance in a high temperature process vessel while it is at or near its operating temperature so that the distal end of the tubular lance structure is adjacent to a place on a wall of the process vessel to be repaired allowing a The lance operator drives it out of the process vessel during the repair of it; a supplying tube within the structure of the tubular lance to supply a refractory, fibrous material, which can be pumped to the distal end of the lance; and an atomizing tube in thermal contact with the structure of the tubular lance along the length thereof to thereby be thermally protected from the elevated operating temperature of the process vessel to provide an atomizing gas to the distal end of the next lance from the distal end of the tubular structure of the lance to thereby make an atomized spray of the fibrous refractory material that can be pumped discharged therefrom and onto the walls of the process vessel.

7. The lance of claim 6 further comprises the refrigerant inlet and discharge conduits to allow circulation of a refrigerant through the lance to protect the lance from the elevated temperatures within the process vessel.

8. The lance of claim 7, wherein the atomizing tube is fixed to a surface of the refrigerant inlet duct or the refrigerant discharge duct so as to be in thermal communication with it.

9. The lance of claim 7 or claim 8, characterized in that the material supply tube is positioned concentrically within the coolant inlet duct to define an annular space therebetween, and wherein the atomizing tube is placed within the annular space .

10. The lance of any of claims 7 to 9 further comprises a nozzle structure at the distal end of the tubular structure of the lance.

11. The lance of claim 10, characterized in that the structure of the nozzle is positioned to direct a stream of refractory material, fibrous, that can be pumped, atomized, laterally in relation to the lance.

12. The lance of claim 10 or claim 11, characterized in that the structure of the nozzle is positioned to direct a stream of refractory material, fibrous, that can be pumped, atomized, longitudinally in relation to the lance.

13. A method for repairing a fibrous refractory wall of a process vessel at elevated temperature, comprising the steps of: (a) inserting a heat-protected lance having an atomizing tube in thermal communication with it in the process vessel while the process vessel is at or near its elevated operating temperature so that a nozzle structure of the lance at a distant end of this is placed next to an area of the wall of the process vessel in need of repair, and so that the lance can be handled from outside the process vessel during the repair of the wall thereof; (b) pumping a fibrous, viscous refractory material from a source therefrom from the proximal end of the lance to the structure of the nozzle at the distal end of the lance; directing an atomizing gas through the atomizing tube so that the atomizing gas causes the fibrous refractory material to be discharged from the nozzle structure of the lance in the form of an atomized spray; and operating the lance from the outside of the process vessel to cause the atomized spray of the fibrous material to make contact with the wall of the process vessel for repair by this means.

14. The method of claim 13, which consists in circulating a liquid refrigerant through the lance into the liquid inlet and discharge conduits.

15. The method of claim 14, which consists in fixing the atomizer tube to a surface of the liquid inlet or discharge conduit.

16. The method of claim 14 or claim 15, which consists of pumping the fibrous refractory material through a supply tube of material placed concentrically within the liquid inlet duct, and placing the atomizing tube within an annular space defined between the material supply tube and the liquid inlet conduit.

17. The method of any of claims 13 to 16, which consists in directing the atomized spray of the material in a generally transverse direction in relation to the lance.

18. The method of any of claims 13 to 17, which consists in directing the atomized spray of material in a generally axial direction in relation to the lance. SUMMARY OF THE INVENTION The systems (10) and the methods by which the fibrous, viscous, pumpable material can be applied to surfaces of high temperature process vessels (12) when hot (i.e. when at temperatures or temperatures) are described. near the high operating temperatures of containers of several hundred to several thousand degrees Fahrenheit). More specifically, a spear is preferably provided (14, 30) having a nozzle structure (14-5) at a distal end thereof, and a pumping system (18) for pumping refractory, fibrous, pumpable material to the nozzle (14-5) . The lance (14) is of sufficient length to allow it to be inserted into the high temperature process vessel (12) so that the structure of the nozzle (14-5) is adjacent to an area that needs repair while an operator holds a proximal end thereof outside the container (12). During use, the lance (14, 30) is inserted into the process vessel (12) when the process vessel (12) is at or near the high operating temperature so that the structure of the nozzle (14- 5) is placed next to an area of the wall of the process vessel that needs to be repaired, and so that the lance (14, 30) can be operated from the outside of the process vessel (12) during the repair of the wall of this one The operation of the lance (14, 30) from the outside of the process vessel will cause the atomized spray of the fibrous material to make contact with the wall of the process vessel (12) thereby repairing the wall.